Braess’ Paradox and Times Square’s Pedestrian Plaza
https://www.nytimes.com/2010/02/12/nyregion/12broadway.html
https://www.nytimes.com/2009/02/26/nyregion/26broadway.html
Braess’ Paradox explains the reasoning behind the seemingly counterintuitive notion that often times, adding a road can increase traffic congestion, while removing or blocking off a road will have the opposite effect. The paradox can be framed from a Prisoner’s Dilemma perspective, where in a Prisoner’s Dilemma, players in totality would be better off if they made decisions that benefited the group as a whole, but rationally are not inclined to do so since an act of selfishness is always a better strategy for themselves in response to what the other players decide to do. Reframing this in terms of Braess’ Paradox, it is evident in many cases that drivers would be able to reach their destination earlier if they decide to equally move along two separate paths to the same destination, but the opening of a third far shorter road connecting the two paths encourages a new seemingly shorter path, which ironically ends up creating greater traffic problems for everyone involved. Any individual driver that tries to revert to the old strategy will end up taking far longer than if they also went with the crowd mentality of taking this new shortest road, and hence all drivers end up in a Nash Equilibrium of unintended and unwanted traffic for everyone.
This paradox was partially the motivation behind NYC’s move to convert Times Square from a busy street to a pedestrian plaza back in 2009, closing it off to cars. The New York Times article New York Traffic Experiment Gets Permanent Run outlines the success of the project, highlighting, among other improvements such as decreased accidents, pedestrian injuries, and crime rates, the greatly decreased traffic of the area. The article claims that “Traffic along Seventh Avenue, for example, moved 4 percent faster,” and that “Travel times along that avenue [the Avenue of the Americas] improved by 15 percent, according to the city’s data.” Additionally, “northbound travel times improved by 17 percent,” according to “numbers [which] encompassed 1.1 million Midtown taxi trips taken between Fifth and Ninth Avenues in Midtown”.
The relative success of this project, even though it wasn’t up to par with previous expectations, brings to light the effectiveness of Braess’ paradox, the Prisoner’s Dilemma, and Nash equilibria in describing real life traffic and infrastructure scenarios. When the collective mindset of individuals fail to tend towards an optimal solution, it helps to take a step back, draw upon the wisdom of game theory and the study of networks, and apply potentially counterintuitive solutions that may end up being of great benefit to all.